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Audio Question
by Ben Whyall 05 Dec '17

05 Dec '17

Hi I have a query which whilst not 100% linux I suspect someone might be able to help. I want to be able to somehow share speakers, and headphones/headset between two systems. Ideally I want to be able to decide what output is in use by ficking a switch or something similar not unplugging. Same with the input. One machine is a linux box and one is my work laptop (windows 10) What are peoples thoughts? Ben

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Firefox 57 woe
by Bev Nicolson 30 Nov '17

30 Nov '17

I had hoped to be prepared for whenever the upgrade to Firefox 57 occurred but it turns out I haven't been. This is because the Software Updater hadn't offered 57. Anyway, it seems I have lost all my ScrapBook pages. Or at least, the question I want to ask is, how can I find out for sure that I have? The home and computer directory have been searched for 'firefox data' but no dice. Bev.

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ssh_config file equivalents of command line options - how to find?
by Chris Green 30 Nov '17

30 Nov '17

I had a hard time recently working out what the ssh_config file equivalent of the -L command line option in ssh was. The man page happily tells you that "Port forwardings can also be specified in the configuration file." buut doesn't tell you *what* the configuration file equivalent is. (It's actually a bit obvious - LocalForward). Is there any documented way of finding the mapping? I'm now after the config file equivalents for -f and -N if there are any. -- Chris Green

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2600 meeting at 18:00 on Friday the 1st December.
by Viperfang 30 Nov '17

30 Nov '17

Quick heads up about this months Norwich 2600 meeting, more info at http://www.norwich2600.co.uk

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How to *start* a desktop remotely? (for VNC)
by Chris Green 23 Nov '17

23 Nov '17

How can one *start* a desktop (in my case XFCE on xubuntu) remotely? I have set up VNC to acces my home machine desktop but since it's not actually running a desktop as it's been rebooted the VNC client shows me nothing. Help!? I have ssh access to my home machine. -- Chris Green

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4G data
by Phil Thane 19 Nov '17

19 Nov '17

Hi, Not really a Linux question, except that it'll be mostly Linux devices that use it... A few years ago when 4G was being tested in pilot areas, but not on the Llangollen canal, I wrote a piece for a canal/river boat magazine about using the internet afloat. At the time I borrowed some demo kit from suppliers and a boat from the Llangollen Wharf for testing and for photos. One option was a 3G USB dongle for a laptop, another was a 3G modem/router to create a WiFi hotspot. Or just use my old 3G smartphone and either a USB or WiFi 'tether'. Now down south I've got my own (very old and very cheap) boat and 4G is widely available. So should be great eh? Well not so much. As far as I can find out it is impossible to buy data only SIM cards with data contracts that last until the data is used. You have to buy 'bundles' of data/phonecalls/text and they expire after 7, 14 or 28 days. When I'm not on the boat I don't use 4G at all. When I am going away on it I have to guess how much data I might need and load up the SIM. Last time I did that the boat broke down, we came home early and £20 worth of data just expired at the end of the 28 days. With my old 3G phone (on PAYG) it simply used the same account for texts, calls or data - and I only enabled 3G when I really needed it. But it seems none of the phone providers will offer 4G that way. I can't see there's any technical reason, it's just that phone providers are conniving bastards. Does anyone know of one that has broken ranks with the cartel and will offer me what I want? -- Phil Thane www.pthane.co.uk phil(a)pthane.co.uk 01767 449759 07582 750607 Twitter @pthane

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Python GUIs
by Mark Rogers 10 Nov '17

10 Nov '17

I've only just really started to use Python, so this is very much a novice question. I'd like to create a simple Python GUI to manage a configuration file. I'll be developing it on Ubuntu but it'll need to run cross-platform, which is one reason I picked Python. Anyone here have any recommendations as to the best way to do this? Google gives me hundreds of options which is great but I'm after anecdotes from people I (feel I) know. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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[ALUG Announce] ALUG Norwich Pub Meet Thursday 9th November
by Viperfang 06 Nov '17

06 Nov '17

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce ----- Hello Norwich Aluggers, Our monthly ALUG Norwich social meeting will be held this Thursday, 9th November at The Coach and Horses (82 Thorpe Road, Norwich, NR1 1BA). The meeting officially starts at 8pm, although some people may arrive earlier. More information on those people can be found on the list and the IRC channel. If you are unsure if you will recognise us then make yourself and your intent to attend known by either posting on list or visiting us on IRC so we can look out for you rather than hiding in the corner. Optionally you could ask at the bar if they know where the geeky computer weirdos are and they'll point you in the right direction (seriously!). Another possibility is look for heaps of electronics on a table that may possibly look like movie props that would used for detonating explosives. Feel free to bring electronics/laptops/gadgets to the meet, you will by no means be alone. Ben Bewick aka Viperfang NB: This mail is automated, please refer to the usual sources for more information. ALUG Contact Details: Website : http://www.alug.org.uk/ IRC : #alug on irc.alug.org.uk List : http://lists.alug.org.uk/mailman/listinfo Twitter : http://twitter.com/anglianlug Identica: TBA Facebook: http://www.facebook.com/group.php?gid=2381613902 ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce

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Are there any Regular Expression gurus here?
by Chris Green 30 Oct '17

30 Oct '17

I'm fairly happy most of the time using REs and can come up with some hairy looking stuff occasionally but I can't, at the moment, see a way to do this:- I want to match two lines like the following using a Regular Expression:- abcmnoxyz ========= The first line is essentially random, the second line will be all the same character of a limited number of possibles (=, - and maybe a couple more). The lines can probably be required to be the same length but it would be nice if they didn't have to be. It would be OK to have multiple REs, one for each possible 'underline' character. It's not a fixed length by the way, the minimum length will probably be 4 characters or so. Can anyone come up with a way to do this? -- Chris Green

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Huge increase in spam
by Laurie Brown 26 Oct '17

26 Oct '17

Hi all, Well, after many years of my Linux mail filters working very well, I've noticed a significant increase in spam over the last week, and last night I got 33 alone, an unheard of number. Has anyone else noticed this? I use postfix, blacklists, postgrey, spamassassin (and a Bayesian DB), with all the usual postfix settings to discourage spammers. I also use a honeytrap third party MX server which traps and records some spam. Normally, once in a while I'll see a small increase in soam, and then the RBLs kick in and it stops after a few hours. However, I can't even find much of a pattern in the emails; there are a couple of regular IPs - now firewalled out - but in the main they are random. There must be a massive Windows-based botnet out there with some new spamming software on it. It's certainly dealing with grey-listing now. Ideas anyone? Cheers, Laurie. -- --------------------------------------------------------------------- Laurie Brown laurie(a)brownowl.com ---------------------------------------------------------------------

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JOB | Permanent Cassandra Database Engineer
by James Tobin 16 Oct '17

16 Oct '17

Hello, I'm working with an employer that is looking to hire a permanent Cassandra database engineer. Consequently I had hoped that some members of this mailing list may like to learn more and discuss further. I can be reached off-list using "JamesBTobin (at) Gmail (dot) com". Kind regards, James

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wake up GUI
by Phil Thane 13 Oct '17

13 Oct '17

OK, I'm inviting trouble here but bear with me. I run an old desktop PC, headless as a file/webserver. My wife's PC backs up to it and I mirror most of my desktop on it using Nextcloud. My only previous experience with web servers has been running Wordpress etc on hosted platforms whee all the setup stuff is done via Cpanel. No Cpanel on my DIY server though so to make life easier it runs a desktop distro (currently Lubuntu) and VNC. I can do any admin via KRDC from my desktop. During set up all this works OK, but the Lubuntu desktop goes blank after a few minutes inactivity, KRDC connects fine but all I see is black screen. The only way I can find to get back in is to reboot (using SSH), restart VNC then re-connect KRDC before the blackout kicks in. A while ago I did this and tried to find a setting to keep the screen alive for ever, as there's no actual screen attached it would make little difference to power consumption. I thought I'd found it, but obviously not as it still blanks. Anyone got any idea? I'm not totally averse to CLI work, providing it's a simple command to solve a specific issue like this, but I really don't want to learn how to do everything I need to do on the server that way! -- Phil Thane www.pthane.co.uk phil(a)pthane.co.uk 01767 449759 07582 750607 Twitter @pthane

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Controlling a Raspberry PI I/O pins via web App
by steve-ALUG＠hst.me.uk 12 Oct '17

12 Oct '17

Can any Raspberry Pi users out there or web people help? I Want to use webpage to control Neopixels plugged into a Raspberry Pi. The webpage will have slider controls for R, G, B & overall brightness. I was initially thinking of using cgi-bin scripts using python, but I want the colour to change as the slider moves so I don't know if that would be responsive enough. Reading around, there seem to be many python-based solutions* so I could use cgi scripts, web sockets, webpy, flask, danjo or others. Anyone got a recommendation of which way to go. Lightweight and no security will do. *I want to use python if possible as that's what I'm most familiar with ATM, with a bit of Javascript as required. Any advice appreciated. Steve

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Ubuntu 17.04 sleeping?
by Clark, Adrian F 12 Oct '17

12 Oct '17

Hello everyone, I have a machine running Ubuntu 17.04 (desktop version) on a Dell Optiplex 5050 which needs to run a long shell script (doing some machine learning runs) overnight. I've turned off suspend via Unity's "power management" control panel but it looks as though the machine still goes to sleep after being left alone for an hour. I wonder if anyone has any suggestions as to what's going on? ..Adrian -- Dr Adrian F Clark WEB: http://privatewww.essex.ac.uk/~alien/ EMAIL: alien/at/essex.ac.uk TEL: +44 1206 872432 RADIO: M0PDF PAPER: Comp Sci & Elec Eng, University of Essex, Colchester, CO4 3SQ, UK "The great tragedy of science: the slaying of a beautiful hypothesis by an ugly fact" -- Huxley

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Controlling a Raspberry PI I/O pins via web App
by Martyn Smith 12 Oct '17

12 Oct '17

I rarely comment on here so I hope I have responded correctly? I have a Pi but I have done very little with python. However, as for a web app solution - although I use C#, PHP (and some Scheme) I would probably be tempted to use web2py if encouraged to use python. Failing that - use something rather popular like Django. Please note that this below is an example. I have *not *tested it (or even downloaded web2py) but I hope this serves as an example for what, I believe, you are trying to accomplish. This code is based on general experience and what the web2py tutorials cover. The only area that needs additonal attention is ensuring the sliders are loaded with the correct values, which I have not done. However, using jquery, I have created an ajax post when the user 'mouse up' on the slider - the values are passed over (which the data variable 'should' be storing in the slider function. again - expect a few hiccups. Hope this helps. *Controller - controls.py* def slider() data = request.post_vars # Do raspberry Pi stuff here # .. or, if not, send to 'some queue' to be processed elsewhere *View - controls/slider.html* <html> <head> <title>Brightness controls</title> <meta charset="utf-8"/> <script src=" https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> </head> <body> <form method="post" action="/controls/slider"> <input id="brightnessR" type="range" min="0" max="100" step="5" /> <input id="brightnessG" type="range" min="0" max="100" step="5" /> <input id="brightnessB" type="range" min="0" max="100" step="5" /> </form> <script type="text/javascript"> function update() { alert("updating"); $.post('/controller/method', { red: $("#brightnessR").val(), green: $("#brightnessG").val(), blue: $("#brightnessB").val() }); } $(document).ready(function() { $("#brightnessR").mouseup(update); $("#brightnessG").mouseup(update); $("#brightnessB").mouseup(update); }); </script> </body> </html>

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[ALUG Announce] ALUG Norwich Pub Meet Thursday 12th October
by Viperfang 11 Oct '17

11 Oct '17

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce ----- Hello Norwich Aluggers, Our monthly ALUG Norwich social meeting will be held this Thursday, 12th October at The Coach and Horses (82 Thorpe Road, Norwich, NR1 1BA). The meeting officially starts at 8pm, although some people may arrive earlier. More information on those people can be found on the list and the IRC channel. If you are unsure if you will recognise us then make yourself and your intent to attend known by either posting on list or visiting us on IRC so we can look out for you rather than hiding in the corner. Optionally you could ask at the bar if they know where the geeky computer weirdos are and they'll point you in the right direction (seriously!). Another possibility is look for heaps of electronics on a table that may possibly look like movie props that would used for detonating explosives. Feel free to bring electronics/laptops/gadgets to the meet, you will by no means be alone. Ben Bewick aka Viperfang NB: This mail is automated, please refer to the usual sources for more information. ALUG Contact Details: Website : http://www.alug.org.uk/ IRC : #alug on irc.alug.org.uk List : http://lists.alug.org.uk/mailman/listinfo Twitter : http://twitter.com/anglianlug Identica: TBA Facebook: http://www.facebook.com/group.php?gid=2381613902 ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce

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calendar and Nextcloud
by Phil Thane 06 Oct '17

06 Oct '17

I did it a disservice earlier, installing the upgrade of Nextcloud to version 10.*.* doesn't actually remove the calendar and contacts apps, it just disables them re-enabling them restores them without loss of data. Hopefully this manual upgrade is a one-off and in future the automagical system will work. -- Phil Thane www.pthane.co.uk phil(a)pthane.co.uk 01767 449759 07582 750607 Twitter @pthane

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Calendar server recommendations wanted
by Chris Green 06 Oct '17

06 Oct '17

I've been using OwnCloud for a few years but it really is becoming a bit of a pain to support. Well, it always *was* a pain to support and now I'm getting fed up with maintaining it. There's all sorts of (minor, but they add up) issues with it:- Upgrading is a pain, doesn't "just work". Various messages aboout security which don't link to anywhere useful. Basic Calendar and AddressBook apps aren't built-in, have to be re-enabled at each upgrade. Just messy generally! So I'm considering alternatives. I need a calendar server which supports Linux (Thunderbird/Lightning) and Android clients, if it does address lists as well then so much the better but that's not vital. Any recommendations anyone? -- Chris Green

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2600 meeting at 18:00 on Friday the 6th October.
by Viperfang 03 Oct '17

03 Oct '17

Quick heads up about this months Norwich 2600 meeting, more info at http://www.norwich2600.co.uk

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Manipulating files from bash
by Mark Rogers 25 Sep '17

25 Sep '17

There are lots of ways to process text files (eg sed, awk, etc); I'm after suggestions on the best/easiest way to achieve something fairly trivial to describe. Below is example output from sfdisk -d: label: dos label-id: 0xe3f4f21a device: /dev/sdd unit: sectors /dev/sdd1 : start= 8192, size= 85622, type=c /dev/sdd2 : start= 94208, size= 5521408, type=83 /dev/sdd3 : start= 5615616, size= 25499648, type=83 I want to convert this into a new script to go back into sfdisk but with some changes; I want the start values skipped (so sfdisk will put partition boundaries wherever it thinks is best), I want the last sector not have a size (ie "rest of disk"), and I don't really need any of the settings at the top. In fact, a suitable (minimal) script to go into sfdisk would be simply: ,85622,c ,5521408 ,; I don't really mind at this point whether I end up with something more like the first format or minified like the latter. In fact to be honest I'm more interested just in learning the best ways to play with text files like this. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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RPi SD backup/restore
by Mark Rogers 25 Sep '17

25 Sep '17

I've been experimenting with backing up and restoring Raspberry Pi SD cards. There is of-course a very easy way: use "dd" or similar to create a disk image. However it has three disdvantages; it is slow, and it creates very large backups. And it's hard to extract individual files from the backups. I've written up a quick process [1] for doing it manually, which is essentially: 1. Backup (or restore) the partitions using sfdisk 2. (Restore only) Create the filesystems on the destination 3. Backup (or restore) the files using tar. However I'd like some advice on scripting and improving it. In particular, this process creates three files (one for the partition info, and one each for the files from the two partitions). I'd like to end up with a single file, which I can do by just tar'ing the three at the end, but given the size of the files I want to keep the use of temporary files to a minimum. Also, at the moment it's quite inflexible in terms of restoring to a different sized card, but ought not be. But regardless, I figured there'd be enough Pi users around here who might find it useful. (Use at your own risk, it's had very limited testing so far.) [1] https://docs.google.com/document/d/e/2PACX-1vRk_zldu0Ra6MEEepTSKCzD55ANeasQ… -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Disk labels and partition names
by Mark Rogers 22 Sep '17

22 Sep '17

In my experiments with RPi backups, I note that the SD card has a label and that label is used when the partitions are mounted (eg disk label: 0xbff5ebb9, and /etc/fstab using PARTUUID=bff5ebb9-01 and bff5ebb9-02). Is it better that I (a) change my fstab to mount by partition name (/dev/sda1, /dev/sda2) and let the disk labels vary when duplicating across multiple Pi's, or (b) leave fstab to use the disk label and leave it the same across multiple Pi's? There's also option (c) which is to generate a new disk label but update fstab accordingly on restore. I'd rather avoid that unless there's a convincing argument for it though. I guess what I'm asking is how much it matters if lots of Pi's have the same disk label, and also weighed against that how much it is an advantage to mount based on disk ID instead of partition number. Mark -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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[ALUG Announce] ALUG Norwich Pub Meet Thursday 14th September
by Viperfang 14 Sep '17

14 Sep '17

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce ----- Hello Norwich Aluggers, Our monthly ALUG Norwich social meeting will be held this Thursday, 14th September at The Coach and Horses (82 Thorpe Road, Norwich, NR1 1BA). The meeting officially starts at 8pm, although some people may arrive earlier. More information on those people can be found on the list and the IRC channel. If you are unsure if you will recognise us then make yourself and your intent to attend known by either posting on list or visiting us on IRC so we can look out for you rather than hiding in the corner. Optionally you could ask at the bar if they know where the geeky computer weirdos are and they'll point you in the right direction (seriously!). Another possibility is look for heaps of electronics on a table that may possibly look like movie props that would used for detonating explosives. Feel free to bring electronics/laptops/gadgets to the meet, you will by no means be alone. Ben Bewick aka Viperfang NB: This mail is automated, please refer to the usual sources for more information. ALUG Contact Details: Website : http://www.alug.org.uk/ IRC : #alug on irc.alug.org.uk List : http://lists.alug.org.uk/mailman/listinfo Twitter : http://twitter.com/anglianlug Identica: TBA Facebook: http://www.facebook.com/group.php?gid=2381613902 ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce

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Changing a static IP (Rasbian Stretch)
by Mark Rogers 14 Sep '17

14 Sep '17

Note: I have "net.ifnames=0" in /boot/cmdline.txt so that I get the old interface names (eth0 etc) back. I've always worked with /etc/network/interfaces in the past, but Googling suggests the correct way to set a static IP is now to edit /etc/dhcpcd.conf and append: interface eth0 static ip_address=192.168.0.28/24 static routers=192.168.0.1 static domain_name_servers=192.168.0.5 If I restart dhcpcd or networking: sudo service networking restart .. then the new IP address gets added, but the old IP address gets retained until reboot. (Regardless of whether the old IP came from DHCP or was a previous static.) What am I doing wrong? Note: If there's a better way to set a static IP then I'm happy to look at that instead. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Intelligently deleting thumbnail images
by Mark Rogers 07 Sep '17

07 Sep '17

A friend lost all their photos from their phone; luckily they had been on a MicroSD card and photorec recovered them all for me, and renrot renamed them all (and fixed their timestamps) based on their EXIF data. So what I now have is a directory of images, but of-course the phone had created thumbnails and the recovery has recovered them as well, and I'd like to delete them. As a human it's easy to do: find two images that "look" the same, and delete the smaller one. But there are hundreds so this human isn't up for the job. Any suggestions as to how to do this in software? Just deleting all the smaller images isn't enough as there do seem to be some small images for which there isn't a larger counterpart (I'm guessing maybe they came from the front facing camera or some other source). -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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